Causes of Facial Numbness
Facial numbness is a distressing symptom most commonly limited to one side of the face, although both sides are sometimes affected 5. The numbness can manifest as reduced sensitivity to a complete lack of sensation. Facial numbness occurs with a wide range of medical conditions, some much more serious than others 5. The specific part of the face affected and the presence or absence of accompanying signs and symptoms help narrow the lengthy list of possible culprits.
Traumatic Nerve Damage
The trigeminal nerve -- also known as cranial nerve V or CN V -- carries sensation signals from the face and front of the scalp to the brain, where they are interpretted. Traumatic damage to any of the three branches of this nerve can lead facial numbness 5. This might occur due to a facial or skull injury, or accidental nerve injury during a dental procedure or surgery involving the face or brain. The three branches of CN V on each side of the face and the areas they innervate are:
- The trigeminal nerve -- also known as cranial nerve V or CN V -- carries sensation signals from the face and front of the scalp to the brain, where they are interpretted.
Nontraumatic Nerve Damage
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A variety of ailments can lead to nontraumatic trigeminal nerve damage and facial numbness 5. Longstanding diabetes can damage nerves anywhere in the body including branches of CN V, although this is uncommon. Sickle cell disease can cause damage when mishapen red blood cells block capillaries and deprive the nerve(s) of oxygen. A molar tooth abscess can potentially damage a branch of CN V by compressing it. Head and neck, facial skin cancers, and cancers that spread from elsewhere in the body can cause facial numbness if they compress or invade a branch of CN V 5.
Facial numbness can accompany certain cranial nerve disorders 5. Bell palsy, for example, primarily affects the facial nerve causing temporary paralysis on one side of the face. For reasons that are incompletely understood, the trigeminal nerve can also be involved leading to facial numbness on the affected side 5. Another condition called trigeminal neuralgia is characterized by brief but excruciating shooting pains in the face. Between these episodes, the affected side of the face typically exhibits decreased sensation.
- A variety of ailments can lead to nontraumatic trigeminal nerve damage and facial numbness 5.
Central Nervous System Disorders
Several disorders of the central nervous system -- the brain and spinal cord -- can potentially cause facial numbness 5. Tumors involving the brainstem might cause this symptom, which is usually accompanied by other signs and symptoms that vary depending on the exact location and size of the growth. Acoustic neuroma, a noncancerous tumor of the nerve that carries signals betweeen the inner ear and brain, can cause facial numbness and weakness along with hearing loss, ringing in the affected ear and a spinning sensation 15.
Stroke and a transient ischemic attack -- commonly known as a TIA or mini stroke -- are important considerations with sudden facial numbness 5. Multiple sclerosis can also cause facial numbness, although this is uncommon 5.
Other Causes
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- Bleeding into the brainstem
- Brainstem blood vessel malformation
- Cholesteatoma, a noncancerous middle ear tumor
- Pituitary gland tumor
- Certain drugs, such as:
- fertilizers
- pesticides
- arsenic
- Brass instrument (trumpet
- tuba or French horn) neuropathy
- a cause upper lip numbness
- Rarely
- systemic lupus erythematosus or rheumatoid arthritis
Warnings and Precautions
- Sudden, severe neck pain or headache
- Sudden visual changes, such as vision loss or double vision
- Sudden dizziness or a spinning sensation
- Numbness, weakness or paralysis on one side of the body
- Slurred speech, difficulty swallowing or drooling
- Confusion, agitation, drowsiness or other mental changes
- Decreased coordination or difficulty walking
- Unequal pupil size
- Involuntary eyeball movements
- Drooping jaw or upper eyelid :
Related Articles
References
- Neupsy Key: Approach to the Patient With Facial Numbness
- Journal of the Canadian Dental Association: Management of Unilateral Facial Numbness
- Evidence-Based Medicine Consult: Dermatomes of the Face
- Dartmouth College: Evaluation of the Patient With "Numbness"
- DocNeuro.com: Facial Numbness
- Kochhar A, Larian B, Azizzadeh B. Facial Nerve and Parotid Gland Anatomy. Otolaryngol Clin North Am. 2016;49(2):273-284. doi:10.1016/j.otc.2015.10.002
- De Seta D, Mancini P, Minni A, et al. Bell's Palsy: Symptoms Preceding and Accompanying the Facial Paresis. ScientificWorldJournal. 2014;2014:801971. doi:10.1155/2014/801971
- Centers for Disease Control and Prevention. Stroke Signs and Symptoms. Updated January 31, 2020.
- Bhupal HK. Ramsay Hunt syndrome presenting in primary care. Practitioner. 2010;254(1727):33-35, 3.
- National Institute of Neurological Disorders and Stroke. Guillain-Barré Syndrome Fact Sheet. Updated August 13, 2019.
- National Institute of Neurological Disorders and Stroke. Cerebral Aneurysms Fact Sheet. Updated August 13, 2019.
- Jowett N. A General Approach to Facial Palsy. Otolaryngol Clin North Am. 2018;51(6):1019-1031. doi:10.1016/j.otc.2018.07.002
- Jin H, Wang S, Hou L, et al. Clinical treatment of traumatic brain injury complicated by cranial nerve injury. Injury. 2010;41(9):918-923. doi:10.1016/j.injury.2010.03.007
- Chen MC, Tseng TM, Hung SH, Chen PY. Facial nerve schwannoma: A case report and review of the literature. Oncol Lett. 2014;8(6):2787-2789. doi:10.3892/ol.2014.2550
- Karp E, Waselchuk E, Landis C, Fahnhorst J, Lindgren B, Lyford-Pike S. Facial Rehabilitation as Noninvasive Treatment for Chronic Facial Nerve Paralysis. Otol Neurotol. 2019;40(2):241-245. doi:10.1097/MAO.0000000000002107
- Albathi M, Oyer S, Ishii LE, Byrne P, Ishii M, Boahene KO. Early Nerve Grafting for Facial Paralysis After Cerebellopontine Angle Tumor Resection With Preserved Facial Nerve Continuity. JAMA Facial Plast Surg. 2016;18(1):54-60. doi:10.1001/jamafacial.2015.1558
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Writer Bio
Dr. Tina M. St. John owns and operates a health communications and consulting firm. She is also an accomplished medical writer and editor, and was formerly a senior medical officer with the U.S. Centers for Disease Control and Prevention. St. John holds an M.D. from Emory University School of Medicine.